| LEIGHTON HERITAGE GROUP | ||||
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THE BLAST FURNACE LINKS |
HOW THE BLAST FURNACE WORKS |
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1. Water, diverted from a
stream, drove the water wheel which turned the cam (2) and compressed
the huge bellows (3) that were originally fixed to the floor. Counterweights (3a) pulled them open ready for the cam to send the next blast into the 'tuyeres' (pronounced 'tweeres') and into the coupola (6) |
5. Iron ore, charcoal and
limestone were tipped into the coupola from the charging platform
and burnt. The blast from the bellows increased the temperature to about 1300deg F (700deg C) which melted the iron. Limestone was used as flux to help remove impurities. |
6.
When enough ore has melted the furnace was 'tapped', usually
about every twenty-four hours.
The first step was to tap and run off the 'slag' that held the
impurities and unwanted elements. Only then was the molten iron
tapped and run into moulds. These
moulds might be for items such as cooking pots or even, during
the Civil War, cannon and musket balls. Often it was turned into pig-iron that was later re-melted for other uses. |
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